BODC HEADED DOCUMENT NO. 32428 Applies to BODC Series Ref. Nos.: 36734, 36746, 36758, 36771, 36783, 36795, 36802, 36814, 36851, 36863, 36875, 36887, 36899, 36906, 36918, 36931, 36943, 36955, 36967, 36979, 36980, 36992, 37006, 37018, 37031, 47209, 47210, 47222, 47234, 47246, 47258, 47271, 47283, 47295, 47302, 47314, 47326, 47338, 47351, 47363, 47375, 47387, 47399, 47406 I.O.S. Data Processing of Off-Shore Pressure Recorder Data Data processing consists of two stages:- 1. Pressures have been sample rate reduced from the basic time step of the recorder to produce the hourly values and have been interpolated by a cubic spline to generate the value on cardinal hours. 2. Instrumental drift has been removed and the drift free series is produced with an artificial mean value, usually of 100mbar.